Prairie
From Glossary of Meteorology
prairie
A flat or gently undulating plain that is grassy and generally treeless; specifically, such an area in southern Canada and the northern and central United States where it extends from the foothills of the Rocky Mountains to about 88°W longitude.
Its climate, with light summer rains and high summer temperatures, is highly favorable for the growth of cereals, but there is a considerable risk of drought especially in certain portions, where a semiarid climate (steppe climate) prevails. The prairie is similar, but not completely analogous, to the steppe regions of Europe and Asia.